The present invention relates to an alarm system, and more particularly to an automobile alarm system with a noise reduction function.
An alarm system is will known in modern living. There is usually defined an area from unauthorized intrusion, in which the alarm system is installed. In the case of an automobile alarm system, a number of patents, such as U.S. Pat. No. 4,794,368 to Grossheim et al. will examplify the state of art.
In general, an automobile alarm system includes a microcomputer to take input from a sensor or sensors and to drive an actuator or actuators for warning purposes. There are various functions in this art has been developed and marketed, such as the uses of RF (Radio Frequency) Remote Control technology, voice synthesizer technology, etc. However, in one aspect, these detract from the main object of the present invention.
The present invention is concentrated on the noise problem, which often cause the CPU to be temporily down or permanently damaged. As to those skilled in the art, they would admit that the noise in the form of voltage may be as high as 400 volts. It will intefere the normal function of the CPU.